Telephone.



No. 669,944. Patented Mar. 12, I90l. A. P. MERRILL &. J. W. HAYS.

TELEPHONE.

(Application filed Jan. 10, 1900,; (No Model.)

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No 669,944. Patented Mar. I2, I901.

A. P; MERRILL 81. J. W. HAYS.

TELEPHGNE.

(Application filed Jan. 10, 1900.; I

(No Model.) 3 Sheets--Sheet 2.

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No. 669,944. Patented Mar. I2, 1901. A. P. MERRILL & J. W. HAYS.

T E L E P H o N E.

(Application filed Jan. 10, 1900.

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Urvi'Tnn STATES PATENT @FFICE.

ALBION PARRIS MERRILL AND JENNY WARD HAYS, OF SAN FRANCISCO, CALIFORNIA.

TELEPHONE.

rEPEGIFIOATION forming part of Letters Patent No. 669,944, dated March12, 1901.

Application filed January 10, 1900. Serial No. 1,008- (No model.)

, transmit sound as originally produced, but reproduce it in decreasedvolume and strength, necessitating the closest attention at the receiverand with the instrument held to the ear in order to distinguish andunderstand the sounds or message transmitted.

It is one object of the present invention to construct a telephone toovercome this objection and render possible the reproduction ortransmission of sound with nearly or quite its original volume andstrength, so that the same will be audible and distinguishable in anypart of a room or chamber in which the receiving instrumentis locatedand Without the necessity of holding an instrument to the car.

A further object is the production of a telephone in the use of which itis not necessary for the party sending a message to approach thetransmitter and talk directly into the same,-as is required in the useof the common types of telephones, but which transmitter will properlytransmit speech or sounds produced in the room in which the transmittersoften the sounds entering the transmitter.

-the receiver-magnet.

tem of wires and switches whereby a transmitter can be cut out while thetelephone is being u ed, so that while sounds will be transmitted to andreceived by oneinstru ment they will not be transmitted from saidinstrument.

A further object is to prevent the formation of a dead-air cushionagainst a receiverdiaphragm, which, if permitted, would prevent thesuccessful operation of the receiver for the intended purpose.

With such and other objects in view the invention is embodied in thenovel parts, arrangement, and combination of parts hereinafterdescribed, and particularly set forth in the claims.

In the accompanying drawings we have illustrated an embodimentv of ourinvention, but desire it understood that we do not limit the inventionin its useful applications to the construction which is there shownsimply to give a better understanding of the invention.

In said drawings, Figure l is a perspective view of the instrumentwithout the electrical connections. Fig. 2 is a longitudinal sectionalview of the transmitter. Fig. 8 is a similar View of the receiver,showing a portion of the box of the instrument and part of Fig. 4 is aperspective View showing two instruments with their electricalconnections. Fig. 5 is a diagrammatic View showing the application ofthe telephone for use in theaters, public halls, or the like. Fig. 6 isa perspective view of a mute intended to be used with the receiver whenit is desired to diminish the volume of the sound so that it may only beheard by the intended person.

Referring to said drawings, wherein like reference characters refer tosimilar parts throughout the several views, A indicates a box whichconstitutes the support and inclosure for the several parts of theinstrument. The receiver, which is indicated at C, is fixed to a part ofthis box, and in order to prevent the formation of a dead-air cushionagainst the diaphragm of the receiver the box is provided with a hole orholes A In this respect the invention differs from the ordinarytelephone in general use in which the receiver is not a fixture of thebox and in which the box is closed. To close the box entirely deadens ormuffles the vibration of the diaphragm, whereas the open framework orperforated box, as shown, insures a louder and clearer reproduction ofthe sound by the receiver. If desired, suitable screens or reticulatedmaterial A may be provided to cover the openings to prevent the entranceof dust or foreign matter into the box.

B indicates a transmitter, which is shown as secured to an extension A.of the rear por tion of the box. The transmitter extends forwardly fromthis extension A over the body of the box A. The transmitter proper maybe of any suitable or preferred construction, it forming no part of thepresent invention, and we have illustrated in the drawings what is knownas the long-distance transmitter. It comprises, briefly stated, asheet-metal box or shell B holding a cup B, of carbon or other suitablesubstance, through which is passed a screw B", to which one of the wiresof the local or primary circuit is attached. An annular groove is formedin the cup B in which groove is placed a ringB conveniently made ofplush, cotton, or felt, and within this ring 13 is located a circularpiece of soft rubber B, provided with circuiar concentric corrugationsor grooves B adapted to hold the carbon granules indicated at 15 13indicates the transmitter diaphragm, which is placed over the granules.Connected to the shell B by means of a bindingscrew B is the other wireof the local or direct circuit.

We make no claim to the portions of the transmitter thus far described,our invention in the transmitter relating to a novel mouthpiece (shownat B) and an outer large front diaphragm B secured over the mouth orarge end of the mouthpiece. Txe mouthpiece is secured in any preferredmanner to the transmittm' proper, and its inner or operative surface isparabolic in contour. The

object of providing the mouthpiece with the inner parabolic surface isto focus the sounds received by the mouthpiece to a given point at thcenter of the transmitter-(iiaphragm B as indicated by the dotted linesin Fig. 2, thereby concentrating the sounds and increasing theefficiency of the transmitter. The diaphragm B is conveniently made ofbladder, paper, parchment, isinglass, or other suitable light materialand is adapted and acts to soften the sounds when the same are tooharshas, for instance, when produced by brass instruments. The diaphragmB creates an aircushion in the mouthpiece between itself and thetransmitter-diaphragm which acts on the transmitter diaphragm. While thediaphragm B provides better results, we do not wish to limit ourinvention necessarily to the employment of the same, as the receiverwill operate in a highly satisfactory manner without said diaphragm.

Referring to the receiver, which is shown in detail in Fig. 3, 0indicates a mouthpiece or trumpet comprising two portions, the outer orlarger portion having, like the mouth of the transmitter, an innerparabolic surface and the inner or base portion C having a 11y perbolicinner surface, which is preferably provided with a lining C", of felt orsimilar material, which is smoothly secured thereto and hassubstantially the same contour as the inner surface of the portion 0 ofthe moutln piece. The portion of the mouthpiece is provided with abase-securing flange C, by means of which it is secured directly to thebox A or a door A of the box. interposed between this flange and the boxor the door is an annular washer or pad C, its purpose being to preventthe resonance of the wood or other material of which the box is formed.

C indicates the diaphragm of the receiver, which, it will be observed,is of com parat ively large area and is secured at its outer circumferential edge to the flange C, an annular pad or washer Cbeing-interposed between the diaphragm and said flange, which padprevents the metallic sound or ring of the base of the mouthpiece beingtransmitted to the receiverdiaphragm.

C indicates an annular pad, which lies flat against the inner surface ofthe diaphragm C and extends over a large part thereof.

The several pads C 0 and 0 together with the diaphragm and flange G, aresecured to the box or box-door in any preferred manner-as, fol-instance,by means of the metallic ring C placed on the pad 0 and secured to thebox, as by screws, (indicated at C.)

It will be noticed from the construction of the reeeiver-mouthpiece, asindicated by the dotted lineb in Fig. 3, that the sounds prod need bythe diaphragm G it' not going out directly through the receiver aredirected onto the parabolic surface of the outward portion from anypoint at which they strike the hyperbolic base portion and that they arere fiected from the parabolic mouth of. the receiver in straight lines.This novel formation of the receiver-mouthpiece affords a deepair-chamber between the diaphragm and the hyperbolic surface of theportion Ciand these, in combination with the parabolic outlet, assistmaterially in the transmission of the sounds, which are delivered infull volume.

The purpose of the pad C, which lies flat agai nstthereceiver-diaphragm, is to limit the circularvibration of the diaphragmto articulate the sound and has the effect of cutting the words andsyllables off short and clear.

TOO

The purpose of the felt lining U in the parabolic portion of themouthpiece is to soften the speech, take away the resonance of themetal, and make the resultant sound more natural. These are vital pointsto successful articulation. It will be observed that the hyperbolic baseportion of the mouthpiece receives the sounds delivered from any part ofthe relatively large diaphragm and reflects the same into the parabolicportion of the mouthpiece and that the parabolic outer portion sends thesounds out in straight lines. Located back of the receiver-diaphragm Ois an electromagnet of the receiver, (indicated at 0 which is shown ashaving spools 0 which are flattened and are placed on tlattened cores,the purpose being to obtain a magnet of large working area and at thesame time one having its force concentrated on the center of thediaphragm. The magnet is supported conveniently by a bracket, such 0secured to the box A or box-door A D indicates an induction coil, whichis shown as located in the inst rumentbox and having, as usual, aprimary and secondary winding.

E indicates a battery for the local circuit located also in the box ofthe instrument.

One battery is provided for each instrument, being connected up in thelocal circuit thereof.

For an understanding of the electrical connections attention is directedparticularly to Fig. t,which illustrates two instruments, eachcomprising a receiver, transmitter, inductioncoil, and local-circuitbattery, the two instruments being electrically connected. It will beobserved that the primary coil of the induction-coil in each instrumentis in and operated by the direct current from the battery of theinstrument E. The receiverin each instrument, on the other hand, isoperated by and located in the secondary or induced current circuit. Thecurrent for each transmitter tiows, say, from the point marked at thebattery E in the upper instrument, (indicated in Fig. 4,) thence alongthe primary-circuit wire F to the primary coil of the induction-coil D,along the wire G tothe transmitter B,through the transmitter along thewire H to the switch J, and thence back to the battery at the placeindicated by the sign by the wire K. The primary circuit of the lower orother instrument shown in Fig. at follows an exactly similar course and,like the primary circuit of the upper instrument, is provided with aswitch. These switches when open not only save the current from thebatteries when the instruments are not in use, but also permit of onetransmitter being cut out when the instruments are being used ,so thatsounds can be received by either instrument, but will not be transmittedfrom the instrument at which the switch is opened.

The receiver-circuit for the receiver of the upper instrument (shown inFig. 4:) is connected with the transmitter of the lower instrument andbegins, say, with the secondary winding of the induction-coil D of saidlower instrument and follows the course indicated by the arrows X alongthe wire a to the post No. l of the lower instrument, along the wire I)to post No. 2 of the upper instrument, thence along wire 0, plate d,flexible connection c, which latter is interposed for the purpose ofpermitting the swing of the door, to post f, thence along wire 9 to theelectromagnet O of the receiver of the upper instrument, thence alongwire ft to post i, tlexible connection j to post No. of the upperinstrument, thence along wire m to post No. 3 of the lower instrumentand wire m which latter is practically a continuation of the wire in,and finally back to the secondary winding of the induction-coil D of thelower instrument, thus com pletiug the receiver-oircuit for the upperinstrument. The circuit for the receiver of the lower instrument followsa like course, as will beseen from Fig. i. It begins, say, with thesecondary winding of the upper coil D, following the course indicated bythe. arrows y along the wire a to post No. l of the upper instrument,the wire I) to post No. 2 of the lower instrument, wire 0, plate (1, andflexible connection 6 to the electromagnet of the receiver of the lowerinstrument, which latter is not shown, thence to the iiexible connectionj, to post No. 3 of the lower instrument, along the wire on in thedirection indicated by the arrow 1 to the post No. 3 of the upperinstrument, wire 712. which latter, like wire m in the lower instrument,is, in effect, a continuation of the wire m, and back to the secondarywinding of the induction-coil D of the upper instrument, thus completingthe circuit.

It is to be noted that the circuit for both receivers is completedthrough a single wire in with its continuations m m In other words,thiswire in is common to both receivercircuits and is, in effect, a thirdwire or single return-wire for both circuits.

M, Fig. 6, indicates a mute or attachment which maybe used in connectionwith the receiver above described when desired. This mute comprises aparabolic trumpet or portion M provided with a suitable handle M whichtrumpet M is adapted to be placed over the funnel-mouth or large end ofthe receiver, as indicated by dotted lines in Fig. 1. It also comprisesa flexible tube M and earpiece M at the end of said flexible tube. Theobject of the mute is to concentrate, deaden, or diminish the volume ofthe sound from the receiver, so that it may be heard only by the personusing the instrument and who holds the earpiece M to the car.

In Fig. 5 of the drawings we have shown diagrammatically one applicationof our improvement, wherein an instrument having a transmitter is shownas located at a convenient point on the stage of a theater, hall, or thelike, said instrument (indicated at 0) being properly connected to otherinstruments 0 O O 0 provided with our novel receivers and located atvarious points about the body of the hall or theater. With thisarrangement the speech or song or other sounds desired to be heard whichare produced on the stage are received by the several instrumeuts aboutthe auditorium and are delivered in full volume at the various pointswhere the instruments are located,

thus enabling the audience in the remote parts of the auditorium to heardistinctly and understand the sounds produced on the stage.

Many other applications of the telephone will readily suggestthemselves.

IVe do not deem it necessary here to go into a lengthy discussion ofthenuinerousand various applications of the apparatus.

It is believed that from the above description and the drawings theoperation of the telephone will be readily understood.

Having thus described the invention, what we claim as new, and desire tosecure by Letters Patent, is-- 1. In a telephone, a receiver, and afixed box or frame on Which the same is mounted and in which theoperating parts of the receiver and battery are located, said box orframe having an opening or openings to prevent a dead-air cushiontherein, substantially as described.

2. In a telephone, a transmitter provided with a mouthpiece having aninner parabolic surface increasing in diameter from the inner small endto the outer large end, and so positioned relative to thetransmitter-diaphragm as to focus the sounds received by the m outhpieceat the center of the diaphragm, substantially as described.

3. In a telephone, a transmitter provided with a mouthpiece having aninner parabolic surface increasing in diameter from the inner small endto the outer large end, and so positioned relative to thetransmitter-diaphragm as to focus the sounds received by the mouthpieceat the center of the diaphragm, and a diaphragm closing the large orouter end of the mouthpiece, substantially as described.

4:. In a telephone, a receiver comprising a diaphragm and a mouthpieceor trumpet for said diaphragm provided With an inner hyperbolic portion,and outer parabolic portion, substantially as and for the purposespecified.

5. In a receiver for telephones, the combination of a support, areceiver-mouthpiece secured to said su pport and having interposedbetween it and said support a cushion or pad, a pad or cushion O on saidmouthpiece, a receiver-diaphragm on said pad G a pad C extending over alarge area of the diaphragm on the side opposite said pad 0 and meansfor securing the several pads and diaphragm to said support,substantially as described.

6. In a telephone, a receiver comprising a diaphragm, and a mouthpieceor trumpet therefor provided with an inner hyperbolic portion, and anouter parabolic portion said inner portion having a soft lining,substantially as described.

7. In a telephone, a box, orframe, a receiver fixed thereon, theoperative parts of which receiver are located in the box or frame, atransmitter fixed on said box, an induction-coil for the transmitterlocated within said box, a battery located in said box or frame, saidbox or frame having an opening or openings to prevent a dead-air cushiontherein, and suitable electrical connections, substantially asdescribed.

In testimony whereof we have signed our names to this specification inthe presence of two subscribing Witnesses.

ALBION lAltRIS Mliltlillili. JENNY WARD lllll'S.

